linux/drivers/hwmon/nzxt-kraken2.c
Krzysztof Kozlowski 98ce1fc134 hwmon: nzxt: constify pointers to hwmon_channel_info
Statically allocated array of pointed to hwmon_channel_info can be made
const for safety.

Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
2023-04-19 07:08:37 -07:00

235 lines
5.4 KiB
C

// SPDX-License-Identifier: GPL-2.0+
/*
* nzxt-kraken2.c - hwmon driver for NZXT Kraken X42/X52/X62/X72 coolers
*
* The device asynchronously sends HID reports (with id 0x04) twice a second to
* communicate current fan speed, pump speed and coolant temperature. The
* device does not respond to Get_Report requests for this status report.
*
* Copyright 2019-2021 Jonas Malaco <jonas@protocubo.io>
*/
#include <asm/unaligned.h>
#include <linux/hid.h>
#include <linux/hwmon.h>
#include <linux/jiffies.h>
#include <linux/module.h>
#define STATUS_REPORT_ID 0x04
#define STATUS_VALIDITY 2 /* seconds; equivalent to 4 missed updates */
static const char *const kraken2_temp_label[] = {
"Coolant",
};
static const char *const kraken2_fan_label[] = {
"Fan",
"Pump",
};
struct kraken2_priv_data {
struct hid_device *hid_dev;
struct device *hwmon_dev;
s32 temp_input[1];
u16 fan_input[2];
unsigned long updated; /* jiffies */
};
static umode_t kraken2_is_visible(const void *data,
enum hwmon_sensor_types type,
u32 attr, int channel)
{
return 0444;
}
static int kraken2_read(struct device *dev, enum hwmon_sensor_types type,
u32 attr, int channel, long *val)
{
struct kraken2_priv_data *priv = dev_get_drvdata(dev);
if (time_after(jiffies, priv->updated + STATUS_VALIDITY * HZ))
return -ENODATA;
switch (type) {
case hwmon_temp:
*val = priv->temp_input[channel];
break;
case hwmon_fan:
*val = priv->fan_input[channel];
break;
default:
return -EOPNOTSUPP; /* unreachable */
}
return 0;
}
static int kraken2_read_string(struct device *dev, enum hwmon_sensor_types type,
u32 attr, int channel, const char **str)
{
switch (type) {
case hwmon_temp:
*str = kraken2_temp_label[channel];
break;
case hwmon_fan:
*str = kraken2_fan_label[channel];
break;
default:
return -EOPNOTSUPP; /* unreachable */
}
return 0;
}
static const struct hwmon_ops kraken2_hwmon_ops = {
.is_visible = kraken2_is_visible,
.read = kraken2_read,
.read_string = kraken2_read_string,
};
static const struct hwmon_channel_info * const kraken2_info[] = {
HWMON_CHANNEL_INFO(temp,
HWMON_T_INPUT | HWMON_T_LABEL),
HWMON_CHANNEL_INFO(fan,
HWMON_F_INPUT | HWMON_F_LABEL,
HWMON_F_INPUT | HWMON_F_LABEL),
NULL
};
static const struct hwmon_chip_info kraken2_chip_info = {
.ops = &kraken2_hwmon_ops,
.info = kraken2_info,
};
static int kraken2_raw_event(struct hid_device *hdev,
struct hid_report *report, u8 *data, int size)
{
struct kraken2_priv_data *priv;
if (size < 7 || report->id != STATUS_REPORT_ID)
return 0;
priv = hid_get_drvdata(hdev);
/*
* The fractional byte of the coolant temperature has been observed to
* be in the interval [1,9], but some of these steps are also
* consistently skipped for certain integer parts.
*
* For the lack of a better idea, assume that the resolution is 0.1°C,
* and that the missing steps are artifacts of how the firmware
* processes the raw sensor data.
*/
priv->temp_input[0] = data[1] * 1000 + data[2] * 100;
priv->fan_input[0] = get_unaligned_be16(data + 3);
priv->fan_input[1] = get_unaligned_be16(data + 5);
priv->updated = jiffies;
return 0;
}
static int kraken2_probe(struct hid_device *hdev,
const struct hid_device_id *id)
{
struct kraken2_priv_data *priv;
int ret;
priv = devm_kzalloc(&hdev->dev, sizeof(*priv), GFP_KERNEL);
if (!priv)
return -ENOMEM;
priv->hid_dev = hdev;
hid_set_drvdata(hdev, priv);
/*
* Initialize ->updated to STATUS_VALIDITY seconds in the past, making
* the initial empty data invalid for kraken2_read without the need for
* a special case there.
*/
priv->updated = jiffies - STATUS_VALIDITY * HZ;
ret = hid_parse(hdev);
if (ret) {
hid_err(hdev, "hid parse failed with %d\n", ret);
return ret;
}
/*
* Enable hidraw so existing user-space tools can continue to work.
*/
ret = hid_hw_start(hdev, HID_CONNECT_HIDRAW);
if (ret) {
hid_err(hdev, "hid hw start failed with %d\n", ret);
goto fail_and_stop;
}
ret = hid_hw_open(hdev);
if (ret) {
hid_err(hdev, "hid hw open failed with %d\n", ret);
goto fail_and_close;
}
priv->hwmon_dev = hwmon_device_register_with_info(&hdev->dev, "kraken2",
priv, &kraken2_chip_info,
NULL);
if (IS_ERR(priv->hwmon_dev)) {
ret = PTR_ERR(priv->hwmon_dev);
hid_err(hdev, "hwmon registration failed with %d\n", ret);
goto fail_and_close;
}
return 0;
fail_and_close:
hid_hw_close(hdev);
fail_and_stop:
hid_hw_stop(hdev);
return ret;
}
static void kraken2_remove(struct hid_device *hdev)
{
struct kraken2_priv_data *priv = hid_get_drvdata(hdev);
hwmon_device_unregister(priv->hwmon_dev);
hid_hw_close(hdev);
hid_hw_stop(hdev);
}
static const struct hid_device_id kraken2_table[] = {
{ HID_USB_DEVICE(0x1e71, 0x170e) }, /* NZXT Kraken X42/X52/X62/X72 */
{ }
};
MODULE_DEVICE_TABLE(hid, kraken2_table);
static struct hid_driver kraken2_driver = {
.name = "nzxt-kraken2",
.id_table = kraken2_table,
.probe = kraken2_probe,
.remove = kraken2_remove,
.raw_event = kraken2_raw_event,
};
static int __init kraken2_init(void)
{
return hid_register_driver(&kraken2_driver);
}
static void __exit kraken2_exit(void)
{
hid_unregister_driver(&kraken2_driver);
}
/*
* When compiled into the kernel, initialize after the hid bus.
*/
late_initcall(kraken2_init);
module_exit(kraken2_exit);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Jonas Malaco <jonas@protocubo.io>");
MODULE_DESCRIPTION("Hwmon driver for NZXT Kraken X42/X52/X62/X72 coolers");